Nonpolar phase-soluble metathesis catalysts

ABSTRACT

One embodiment of the invention provides polyisobutylene (PIB) oligormers that are end-functionalized with ruthenium (Ru) catalysts. Such nonpolar catalysts can be dissolved in nonpolar solvents such as heptane, or any other nonpolar solvent that is otherwise not latently biphasic (i.e., if two or more solvent components are present, they remain miscible with each other throughout the entire reaction process, from the addition of substrate through to the removal of product). Substrate that is dissolved in the nonpolar solvent with the catalyst is converted into product. The lower solubility of the product in the nonpolar solvent renders it easily removable, either by extraction with a more polar solvent or by applying physical means in cases where the product precipitates from the nonpolar solvent. In this manner the catalysts are recycled; since the catalysts remain in the nonpolar solvent, a new reaction can be initiated simply by dissolving fresh substrate into the nonpolar solvent.

This application is a continuation of U.S. application Ser. No.12/286,745, which claims the benefit of priority to U.S. ProvisionalApplication No. 60/997,093, filed Oct. 1, 2007, which is hereinincorporated by reference in its entirety.

FIELD OF THE INVENTION

The invention relates to methods and compositions useful for catalyzingchemical reactions. In particular, the invention is drawn to reactionsthat afford efficient catalyst recycling and reusability. Even moreparticularly, the compositions and methods provided by the inventionrelate to the provision of a single nonpolar reaction solvent that isnot latently biphasic and a catalyst that is soluble therein.

BACKGROUND OF THE INVENTION

Polymer-supported catalysts are widely used in chemical processes. Muchof the technology that is presently available derives from thesolid-phase peptide synthesis techniques developed by Merrifield. Thesetechniques are based on insoluble cross-linked polystyrene supports.Catalysts supported on Merrifield resins can be recovered from reactionmedia using a solid/liquid separation technique such as filtration.

With the growing interest in environmentally friendly, or “green”chemical processes, there is an emphasis on the ability to reusematerials and to minimize amounts of solvents required for a givenprocess. Filtration is typically a relative solvent-intensive process,because the recovered solid is typically rinsed with additional solvent.Further, some polymer-supported catalysts suffer from decreased activityonce they are isolated via filtration. This impacts their potential tobe reused multiple times.

Soluble polymer-supported catalysts have been developed. These catalystscan be recovered from the reaction medium either by precipitationfollowed by filtration, by liquid/liquid separation, or byultrafiltration using a filtration membrane. Precipitation/filtrationobviously suffers from the same drawbacks associated with the filtrationof insoluble polymer-supported catalysts, described above. Inadequatepartitioning of the catalyst into the desired liquid phase often impairsliquid/liquid separations. For example, liquid/liquid separation isimpractical if the catalyst and the product are both soluble in the samephase. Ultrafiltration of soluble catalysts using membranes has enjoyedsome success, but the recycled catalysts often suffer from some loss ofactivity.

An alternative way of using a soluble catalyst is to use a biphasicsystem wherein the catalyst is preferentially soluble in one phase andthe substrate and/or products are soluble in the other phase. To allowthe reaction to proceed using this setup, the biphasic solvent system isvigorously mixed to ensure maximum contact between the catalyst andsubstrate. After the reaction, the mixture is allowed to settle and theproduct phase is removed, leaving the catalyst phase available for morereactions. This constitutes an example by which the soluble catalyst isrecycled. The drawback to biphasic systems is that the presence ofmultiple phases introduces kinetic barriers to reaction. Such barriersresult for the lack of solubility of both the catalyst and substrate inthe same reaction solvent, which lowers the interaction rate betweenthese reaction components.

The drawbacks associated with biphasic solvent systems can be overcomeby using a solvent system that is monophasic under one set of conditionsand biphasic under a different set of conditions. For example,liquid-liquid biphasic systems that exhibit an increase in phasemiscibility at an elevated temperature and incorporate solublepolymer-bound catalysts having a strong phase preference at ambienttemperature have been described by Bergbreiter and colleagues (2000,2001; both references of which are herein incorporated by reference intheir entirety).

Such thermomorphic biphasic reaction systems are also referred to aslatent biphasic reaction systems, which are described in U.S. Pat. No.7,211,705 (incorporated herein by reference in its entirety). Thispublication describes other latent biphasic reactions where conditionssuch as ion concentration are modified to effect the switch from thebiphasic state (i.e. two or more solvents are immiscible) to themonophasic state in which the solvents become miscible with one another,creating a heterogeneous solvent. Upon reaction completion, the biphasicstate (or multiphasic state) must be restored in order to regain accessto catalyst apart from the product. Consequently, latent biphasicsolvent systems can be rather complex, necessitating the empiricaldetermination of conditions that will effectively govern a reversiblephase transition allowing i) effective mixing of catalyst withsubstrate, and ii) separation of catalyst from product.

A process that is similar to the above-described latent biphasic systemshas previously been described (Bergbreiter et al., 2003). In thatprocess, substrate and soluble catalyst are initially dissolved in ahomogeneous solvent containing at least two different solvents. Theconditions are such that only a slight modification, or perturbation, ofthe reaction system will result in the immiscibility and separation ofthe different solvents (i.e. the system is partly latently biphasic).The strategy in this case is to ensure that the catalyst and reactionproduct are not greatly soluble in the same solvent after systemperturbation. Shared solubility obviously impedes acquisition of purecatalyst.

In view of the prior art, there remains a need for catalytic methodsthat allow for the efficient separation of the catalyst from thereaction product and the recycling of the catalyst. Further, there is aneed for such methods wherein the recycled catalyst is highly reusable.It is desirable that such methods operate with minimal additionalsolvent to effect the separation of the catalyst.

SUMMARY OF THE INVENTION

One embodiment of the present invention is directed to a reactioncomposition that comprises a nonpolar solvent that is not latentlybiphasic, a catalyst that is complexed to a nonpolar support (i.e.,catalyst-support complex), and a molecule that is a substrate for thecatalyst. With this embodiment, the catalyst-support complex andsubstrate molecule are both dissolved in the nonpolar solvent; however,the product of the reaction is less soluble in the solvent compared tothe molecule. In other embodiments of the composition, the product iscompletely insoluble in the solvent. The partial or completeinsolubility of the product in the reaction solvent, coupled with thecomplete solvency of the catalyst-support complex, allows for the facileseparation of the product from the catalyst; the latter component canthus be recycled for another round of substrate-to-product conversion.

Certain embodiments of the reaction composition incorporate anucleophilic organic group as the catalyst. An example of such acatalyst would be a type of a triorganophosphine. In other embodiments,the catalyst comprises an imidazole group, thiazole group, or pyridinegroup. The catalyst of the present invention can also be, moregenerally, a hydrocarbon, a hydrocarbon containing one or more estergroups, a hydrocarbon containing one or more ether groups, or ahydrocarbon containing one or more amine groups. The catalyst can alsocomprise a metal; examples include ruthenium and silver.

The nonpolar support of the inventive composition can comprise, forexample, polyisobutylene, polyethylene, poly(N-octadecylacrylamide),polysiloxane, polyamidoamine, poly(1-alkene), or polypropylene. AnN-heterocyclic carbene moiety or benzylidene moiety, for example, can beused to bridge the catalyst to the support. Components that are chosento attach to the support and act as a ligand for the catalyst should notimpede the ability of the resulting catalyst-support complex to dissolvein a nonpolar solvent.

In other embodiments of the inventive composition, the solventincorporated therein is toluene, dichloromethane, dibutyl ether, or analkane. A preferred embodiment incorporates heptane. Some embodimentscomprise a single solvent component, whereas other embodiments comprisea mix of one or more solvents. In the latter case, the solvent mixshould not be latently biphasic under the conditions (e.g., temperature,salt, pressure) employed during the reaction. Indeed, the presentinvention may incorporate solvent mixtures that have the potential tobehave in a latent biphasic manner; however, such incorporation in thepresent invention is only under reaction conditions that do not inducethe latent biphasic nature of the chosen solvent mix. In other words,even though the solvent mix used in the invention may be latentlybiphasic, such a property is not involved in the reaction—the solventremains monophasic throughout the entire reaction and also during theremoval of product.

Certain embodiments of the reaction composition comprise molecules thatcan be substrates in a ring-closing, ring-opening, or cross metathesispolymerization reaction. Preferred embodiments employ substrates thatcan undergo ring-closure.

In a particularly preferred embodiment of the instant invention, thereaction composition comprises heptane as the solvent, a rutheniumcatalyst that is in complex with a polyisobutylene-containing support,and a heptane-soluble substrate molecule. In this embodiment, thecatalyst-support complex is heptane-soluble, and the substrate moleculeis a substrate for ruthenium. The product of the reaction occurringbetween the ruthenium catalyst and substrate has little or no solubilityin heptane. This feature permits facile separation of the product fromthe catalyst, the latter of which can then be used in a reaction withnewly added substrate. Certain aspects of this embodiment may alsoincorporate an N-heterocyclic carbene moiety as a bridge between thepolyisobutylene support and the ruthenium complex.

The instant invention is also drawn to a method of catalyzing a chemicalreaction having the steps of providing a reaction composition asdescribed above, allowing the substrate molecule to be catalyzed intoproduct, and separating the product from the reaction composition. Theproduct separation step can be performed in different ways. One strategyfor separation is through the use of physical means, such as siphoning,filtering, or decanting, all of which can be employed if the product isnearly or totally insoluble in the solvent. Another strategy forseparation is through extraction of the product by adding and removing asecond solvent to the reaction composition; the second solvent can be apolar organic solvent such as acetonitrile, for example. In this latteraspect of the inventive method, the product is preferably soluble in thesecond solvent compared to the nonpolar solvent of the reactioncomposition. Throughout either process (physical separation orextraction), the catalyst-support complex remains dissolved in thenonpolar solvent. This feature allows for the step of reusing thecatalyst-support complex by dissolving fresh substrate into the nonpolarsolvent.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a ring-closing metathesis reaction catalyzed by anend-functionalized polyisobutylene (PIB)-bound Ru metathesis catalyst.Refer to Study 1.

FIG. 2 shows a reaction scheme for the synthesis of a PIB-supportedsecond-generation Hoveyda-Grubbs catalyst. The numbers shown in bold(1-7) refer to the different molecules involved in this process. Referto Study 1.

FIG. 3 shows the ¹H NMR spectrum of a PIB-bound ruthenium metathesiscatalyst 7 showing changes in the i-Pr heptet in insets a and b for 5and 7, respectively. Molecules 5 and 7 are depicted in FIG. 2. Refer toStudy 1.

FIG. 4 shows a ring-opening metathesis polymerization (ROMP) reactionusing catalyst 7. The numbers shown in bold (18 and 19) refer to thedifferent substrates used in the ROMP reaction. Refer to Study 1.

DETAILED DESCRIPTION OF THE INVENTION

The instant invention provides a catalysis system having a singlenonpolar reaction solvent that is not latently biphasic. The solvent mayconsist of one or more nonpolar liquid components. Solvents consistingof only one component are inherently monophasic and are thus incapableof being latently biphasic. For those solvents having multiplecomponents, the components remain miscible with each other (i.e. remainmonophasic) throughout the entire reaction process (i.e. they do notseparate to different phases upon some form of manipulation), from theaddition of substrate to the removal of product. This system thus doesnot necessitate the provision of latent biphasic reaction schemes, whichinvolve rather complex manipulations (e.g. specific temperature or ionicstate changes). The inventive reaction scheme allows for the catalystand substrate to be soluble in the single nonpolar solvent.Surprisingly, the reaction products are easily separated from thenonpolar solvent by virtue of the products' own lack or lower degree ofsolubility therein, which permits efficient recycling of the catalyst.This key feature distinguishes the present invention from othermonophasic systems. Product removal can be performed by simple isolationof reaction precipitate, or in cases where the product does not readilyfall out of solution from the nonpolar solvent, by introducing a secondsolvent that is immiscible with the reaction solvent and capable ofsolvating the product but not the catalyst. Importantly, neither ofthese separation steps involve manipulating the catalyst itself (e.g.,mobilizing the catalyst from one solvent to another); consequently,enhanced catalyst reusability characterizes the enhanced recyclingprovided by the instant invention.

The instant invention incorporates one or a mixture of nonpolar solventsin which the above reaction takes place. Such solvents include, forexample, hydrocarbon solvents such as toluene, benzene and xylene (i.e.aromatic solvents), and saturated hydrocarbons such as propane, butane,pentane, hexane, cyclohexane, heptane, octane, nonane, decane anddodecane, which may also be used in branched form. Other nonpolarsolvents include mineral oils, natural oils and synthetic oils as wellas mixtures thereof. Still other nonpolar solvents useful in practicingthe instant invention are dichloromethane and dibutyl ether.

The instant invention incorporates a nonpolar support which is solublein a nonpolar solvent. During the course of the inventive reactionprocess, the support remains dissolved in the nonpolar solvent.Non-limiting examples of materials/polymers suitable for preparing thesupport are polystyrene, polycarbonate, polyacrylates, polylactic acid,polyglycolic acid, polycaprolactone, polyisobutylene, polyethylene,poly(N-octadecylacrylamide), polysiloxane, polyamidoamine,poly(1-alkene), polypropylene, polymethyl(meth)acrylate,polyethyl(meth)acrylate and polybutyl(meth)acrylate. In general,oil-soluble polymers can be used as support materials. The support cancomprise one or more different materials.

With respect to solubility of the various components of the invention(e.g., catalyst-support complex, substrate molecule, product molecule),“soluble” is defined as when a mixture (e.g., substrate in nonpolarsolvent) is homogeneous, not turbid, and without substantially anyundissolved residue; whereas “insoluble” is defined as when a mixture(e.g., product in nonpolar solvent) is not homogeneous or is overlyturbid. Partial solubility refers to when parts of the material remainsolid or in a gel form when attempting to dissolve the material in thesolvent.

In certain embodiments of the invention, the catalyst componentcomprises a nucleophilic organic group. Non-limiting examples of suchmoieties are phosphines such as triorganophosphines (e.g.,triphenylphosphine) and BINAP(2,2′-bis(diphenylphosphino)-1,1′-binaphthyl). The nucleophilic organicgroup incorporated in the invention can serve to bind certain catalyticmetal ligands. Suitable metal catalysts that can be incorporated in theinvention include, but are not limited to, iron (Fe), ruthenium (Ru),cobalt (Co), rhodium (Rh), iridium (Ir), nickel (Ni), palladium (Pd),platinum (Pt), copper (Cu), silver (Ag) and other transition metalcatalysts familiar to those skilled in the art (e.g., molybdenum,scandium, titanium, vanadium, chromium, manganese, yttrium, zirconium,niobium, technetium, hafnium, tantalum, tungsten, rhenium, osmium, gold,rutherfordium, dubnium, seaborgium, bohrium, hassium, meitnerium,darmstadtium, roentgenium). Other metals useful for practicing theinvention are selected from the alkali metals, alkaline earth metals,poor metals, and lanthanoids.

N-Heterocyclic carbene (NHC) groups can be used as moieties to bridgethe support with the catalyst. For example, NHC groups can be complexedto a support material, after which the NHC group is used to complex acatalytic metal. For example, NHC groups can be used to form transitionmetal carbene complexes on the support. Different types of NHC groupsthat can be incorporated in the instant invention include, for example,imidazol-2-ylidenes (e.g., 1,3-positions functionalized with alkyl,aryl, alkyloxy, alkylamino, or alkylphosphino groups),triazol-5-ylidenes, cyclic diaminocarbenes, and heteroamino carbenes.

Polar organic solvents may be employed when practicing the invention toaccess certain reaction products that do not readily fall out ofsolution from the nonpolar solvent. To do so, one would generally employa standard extraction procedure with the polar organic solvent toseparate the product from the nonpolar solvent. When performing such aprocedure, the extent to which the catalyst-support complex mighttransfer from the nonpolar solvent to the polar organic solvent shouldbe determined. Obviously, in order to maximize product purity andminimize catalyst loss, one would choose a polar organic solvent thatdoes not favor phase-transfer of the catalyst-support complex. Differentpolar organic solvents can be employed when practicing the instantinvention such as certain alcohols and ethers. Non-limiting examples ofpolar organic solvents include methanol, acetonitrile, DMSO,isopropanol, tetrahydrofuran (THF), hexafluoroisopropanol (HFIP),N-methyl-2-pyrrolidone (NMP), dimethylacetamide, N,N-dimethylformamide,1,2-dimethoxyethane, ethylene glycol, propylene glycol, sulfolanes, anddiethylene glycol alkyl ethers (e.g., diethylene glycol monobutylether). Other polar organic solvents include amine compounds andalkanolamine compounds (e.g., two carbon atom linkage alkanolamines suchas aminoethyleethanolamine [AEEA]).

The present invention is can be employed to carry out different types ofreactions, such as ring-closing, ring-opening and cross metathesispolymerization reactions.

EXPERIMENTAL

Study 1

Herein described is an alternative approach using a heptane-solublepolymer to prepare a second-generation Hoveyda-Grubbs catalyst forruthenium (Ru)-catalyzed metathesis polymerizations that is recoverableand reusable in hydrocarbon solvents by liquid/liquid or liquid/solidseparations after catalysis.

Ru-catalyzed ring-closing metathesis, cross metathesis, and ring-openingmetathesis polymerization have developed into broadly usefulmethodologies (Chauvin, 2006; Grubbs, 2006; Trnka and Grubbs, 2001).These homogeneously catalyzed reactions are equally useful in complexsyntheses and in the formation of materials. For use in these reactions,end-functionalized polyisobutylene (PIB)-bound Ru metathesis catalysts,which are nonpolar and heptane-soluble, can be transformed fromterminally vinyl-functionalized PIB oligomers. FIG. 1 depicts aring-closing metathesis reaction catalyzed by such a catalyst.

In this example embodiment of the instant invention, it is shown thatsuch nonpolar catalysts can be used to convert substrate into product ina heptane-based reaction solution, and then recycled by simplegravity-based extraction after addition of a heptane-immiscible, morepolar solvent. Since the reaction product preferentially dissolves inthe more polar solvent, it is mobilized out of the heptane phase,leaving the catalyst available for another reaction cycle. Furtherdemonstrated by this invention embodiment is the post-reactionacquisition of pure heptane-dissolved catalyst resulting from thecomplete lack of solubility in heptane of the reaction product; underthis scenario, product-catalyst separation is a simple result of productprecipitation from solution. Indeed, many polar organic products of theinventive catalysis are not especially soluble in heptane and can beeasily removed by decantation or filtration. These different routes(liquid/liquid or liquid/solid separation) of catalyst recyclingafforded by the invention are more efficient than those strategiespreviously described (Ahmed et al., 1999; Connon et al., 2002; Garber etal., 2000; Jafarpour and Nolan, 2000; Kingsbury and Hoveyda, 2005;Nguyen and Grubbs, 1995; Yao and Zhang, 2004).

Synthesis of PIB-Supported Grubbs-Hoveyda Second Generation Catalyst

(For molecules 1-7 indicated in bold, refer to FIG. 2) The generalstrategy for synthesis of a heptane-soluble metathesis catalyst reliedon the use of commercially available vinyl-terminated polyisobutylene(PIB). While this material can be >90%=CH2-terminated polyisobutylene 1,some samples contain as much as 20% of the internal double bond (e.g.polyisobutylene 2). A Friedel-Crafts alkylation of either structurallyisomeric polyisobutylene oligomer, however, yields the same4-(polyisobutyl)phenol product 3 (Li et al., 2005). Formylation of thisoligomeric phenol by using paraformaldehyde produces the2-hydroxy-5-(polyisobutyl)benzaldehyde 4. This product can in turn beconverted into the oligomeric styrene derivative 5 by using a Wittigolefination. Exchange of the methylene group with the benzylidene groupof the commercially available second-generation Grubbs catalyst 6produced the desired heptane-soluble catalyst 7. The last step of thissynthesis also used flash column chromatography to separate thePIB-bound Ru complex 7 from starting materials. Chromatography is notusually used in the synthesis of polymer-bound catalysts but is feasiblefor complex 7 just as it is feasible for PEG-bound or dendrimer-boundcatalysts (Garber et al., 2000; Hong and Grubbs, 2006). As is the casefor other terminally functionalized polymer-bound ligands/catalysts, allof the intermediates in these syntheses could be characterized by ¹H NMRspectroscopy (Li et al., 2005; Dickerson et al., 2002; Bergbreiter etal., 1989). FIG. 3 illustrates the sort of ¹H NMR spectra that can beobtained for species such as catalyst 7. This spectrum establishes thatcatalyst 7, in similar fashion to its low molecular weight analogue,involves the isopropyloxy group in the Ru coordination sphere as theheptet due to the CH of the isopropyloxy shifts from δ 4.51 in 5 to δ4.87 in 7 (FIG. 3, compare insets a and b).

Ring-Closing Metathesis Reactions.

(For molecules 8-17 indicated in bold, refer to Table 1) Other thanhaving a PIB-containing ligand rendering catalyst 7 heptane-soluble,this catalyst had normal reactivity, converting a variety of α,ω-dienesinto cyclic olefins at room temperature (Table 1). Catalyst 7 could berecycled multiple times using several different protocols. One approachused for separating products such as 9 and 17 away from the catalyst wasto carry out the ring-closing metathesis reaction in heptane as asolvent and to then extract the products with acetonitrile (Table 1). Insuch cases, the less dense heptane phase contained catalyst 7 andrecycling simply involved addition of fresh substrate.

TABLE 1 Ring-closing metathesis reactions with catalyst 7^(a).

product cycle 1 cycle 2 cycle 3 cycle 4 cycle 5  9 66% 75% 75% 94% 99%11 72% 81% 94% 98% 98% 13 84% 84% 93% 99% 99% 15 67% 76% 84% 84% 93% 1762% 70% 80% 88% 96% ^(a)Yields in cycles 1-5 are of products isolated bysolvent removal.

While catalyst 7 was equivalent in reactivity to the commerciallyavailable catalyst 6, its solubility in heptane and the generally poorsolvating ability of heptane toward many polar organic products makesanother recycling scheme possible. For example, using substrates 10, 12and 14 (Table 1), a reaction was carried out through at least fivecycles by simply adding these heptane-soluble starting materials to theheptane solution of the catalyst. After one hour, the heterocyclicproducts precipitated from the heptane solvent leaving a solution of thecatalyst that can be separated by forced siphon and reused. The apparentincreases in yields from cycles 1-5 in Table 1 reflect saturation of theheptane phase by products (Bergbreiter and Li, 2004; Bergbreiter et al.,2001). If a catalyst were used through multiple cycles this would poselittle problem unless the product or by-products were heptane-soluble(Bergbreiter et al., 2001).

The efficiency of separation of catalyst and product was evaluated byinductively coupled plasma-mass spectrometry (ICP-MS) analysis, using asample of products 9 and 11 from the first and third reaction cycles ofcyclization reactions as shown in Table 1. Combustion of product 9 anddigestion of any residue in concentrated sulfuric acid showed thepresence of about 20 ppm Ru in the product phase. This translates intorecovery of about 97% of the Ru catalyst that is available for a secondreaction cycle. The loss of Ru presumably reflects the fact that thepresent scheme requires the Ru-methylidene intermediate formed from 7 tobe recaptured by 5 formed in situ for complete Ru recovery.Inefficiencies in this process and loss of Ru to another phase are mostnotable in the higher level of Ru contamination in the experiment whereproduct 11 precipitated from heptane. In this case, about 96% of the Rucatalyst was still recovered, but the solid product contained about 1000ppm of Ru. This high concentration of Ru is due to the small volume ofthe product phase and partitioning of Ru species onto the small volumeof the polar solid that is formed. This observation suggests thatdesigning other systems where the Ru species in the catalytic cyclealways has a hydrocarbon soluble ligand may lower Ru leaching.

Ring-Opening Metathesis Reactions.

(For molecules 18-19 indicated in bold, refer to FIG. 4) The reactivityof catalyst 7 was also tested in ring-opening metathesis polymerization(ROMP) reactions (Buchmeiser, 2000; Grubbs and Tuman, 1989). In thiscase, the use of catalyst 7 is expected to generate an amphiphilic blockcopolymer since the PIB chain of the ligand will be the end group of theproduct polymer chain. The ROMP reactions of substrates 18 and 19 withcatalyst 7 were studied in tetrahydrofuran (THF) at room temperature(FIG. 4), using a monomer:initiator ratio of 30:1. ¹H NMR showedquantitative conversion in both reactions after twenty minutes. Thereactions were then quenched with ethyl vinyl ether, and the resultingpolymers were isolated. Catalyst 7 is thus useful in ring-closingmetathesis and ROMP chemistry.

In summary, the studies described above show that PIB oligomersconstitute an excellent heptane-selectively soluble polymer support fora second-generation Hoveyda-Grubbs catalyst. The derivatization andchemistry of these oligomers can be easily monitored by conventionalspectroscopy. The activity of the PIB-supported catalyst is analogous tothat of other soluble polymer or non-supported catalysts.

Materials and Methods (Study 1)

General

The ¹H NMR spectra were recorded on an Inova 500-MHz spectrometeroperating at 499.95 MHz. ¹³C NMR spectra were recorded on an Inova500-MHz spectrometer operating at 125.719 MHz. Chemical shifts werereported in parts per million (δ) relative to residual proton resonancesin the deuterated chloroform (CDCl₃). Coupling constants (J values) werereported in hertz (Hz), and spin multiplicities are indicated by thefollowing symbols: s (singlet), d (doublet), t (triplet), q (quartet),and m (multiplet). UV-Vis spectra were obtained using a Varian Cary 100spectrometer. IR spectra were obtained using a Bruker Tensor 27 FT-IR.ICP-MS were obtained using a Perkin Elmer DRC II instrument.

All reactions were carried out under an inert atmosphere unlessotherwise noted. Acetonitrile, heptane, dimethylformamide, ethanol,dichloromethane, and toluene were purchased from EMD Chemicals, Inc. andused as received. All other chemicals were purchased from Sigma-Aldrichand used as received. Products were isolated simply by evaporation ofsolvent without chromatography. The product spectra contain traces ofalkane solvents, residual polyisobutylene, or water.

Synthesis of PIB-Supported Catalyst 4-(polyisobutyl)phenol

A mixture of 16.75 g (178 mmol) of phenol, 8.9 g (8.9 mmol) ofpolyisobutylene (Glissopal® 1000), and 1.05 g (10.7 mmol) ofconcentrated sulfuric acid in 200 mL of dichloromethane was stirred for3 d at room temperature. The solvent was removed under reduced pressureand then 250 mL of hexanes was added to the viscous residue. The hexanessolution was washed first with 150 mL of dimethyl formamide three timesand then with 150 mL of 90% ethanol/water three times. The hexane phasewas dried over sodium sulfate. The solvent was removed under reducedpressure to yield a light yellow viscous residue. The yield of4-(polyisobutyl)phenol was 70%. ¹H NMR (500 MHz, CDCl₃), δ: 0.8-1.8 (m,138H), 1.8 (s, 2H), 6.75 (d, J=8.79 Hz, 21H), and 7.23 (d, J=8.79 Hz,2H). ¹³C NMR (125 MHz, CDCl₃), δ: 153.19, 142.99, 127.52, 114.75,multiple peaks between 58-60, 38-38.5, and 30.75-33.

2-hydroxy-5-(polyisobutyl)benzaldehyde

A mixture of 3.42 g (3.13 mmol) of 4-(polyisobutyl)phenol and 0.58 mL (5mmol) of 2,6-lutidine in 40 in L of toluene was stirred under roomtemperature for 30 min. A solution of SnCl₄ (0.15 mL, 1.25 mmol) in 10mL of toluene was added slowly to the reaction. The reaction was thenstirred under room temperature for 1 h at which point 0.56 g (18.78mmol) of paraformaldehyde was added to reaction. The reaction was heatedfor 12 h at 100° C. After the reaction mixture cooled to roomtemperature, it was acidified to pH 2.0 with 2M HCl. The organic layerwas separated, the solvent was removed under reduced pressure, and then250 mL of hexanes was added to the viscous residue. The hexanes solutionwas washed first with 150 mL of dimethyl formamide three times and thenwith 150 mL of 90% ethanol/water three times. The hexane phase was driedover sodium sulfate. The solvent was removed under reduced pressure toyield a light yellow viscous residue. The yield of2-hydroxy-5-(polyisobutyl)benzaldehyde was 76%. ¹H NMR (500 MHz, CDCl₃),δ: 0.8-1.8 (m, 155H), 1.8 (s, 2H), 6.94 (d, J=8.54 Hz, 1H), 7.48 (m,1H), 7.57 (d, J===2.44, 8.54 Hz, 1H), 9.9 (s, 1H), and 10.88 (s, 1H).¹³C NMR (125 MHz, CDCl₃), δ: 197.07, 159.65, 142.40, 135.74, 130.73,120.21, 117.24, multiple peaks between 58-60, 38-38.5, and 30.75-33.

2-isoproproxy-5-(polyisobutyl)benzaldehyde

A mixture of 2.5 g (2.25 mmol) of 2-hydroxy-5-(polyisobutyl)benzaldehydeand 0.425 g (2.5 mmol) of isopropyl iodide in 10 mL of DMF and 10 mL ofheptane was heated to 80° C. over night, then cooled to roomtemperature. At this point, 50 mL of hexanes was added to the solution.The hexanes solution was washed first with 30 mL of dimethyl formamidethree times and then with 30 mL of 90% ethanol/water three times. Thehexanes phase was dried over sodium sulfate. The solvent was removedunder reduced pressure to yield the2-isoproproxy-5-(polyisobutyl)benzaldehyde product as a light yellowviscous residue with 76% yield. ¹H NMR (500 MHz, CDCl₃), δ: 0.8-1.8 (m,168H), 1.8 (s, 2H), 4.66 (m, 1H), 6.92 (d, J=9.04 Hz, 1H), 7.53 (d,J=2.69, 8.79 Hz, 1H), 7.82 (d, J=2.69 Hz, 1H), and 10.49 (s, 1H). ¹³CNMR (125 MHz, CDCl₃), δ: 190.68, 158.75, 142.92, 134.06, 125.63, 125.21,113.83, 71.34 multiple peaks between 58-60, 38-38.5, and 30.75-33.

1-isoproproxy-4-(polyisobutyl)-2-vinylbenzene

Methyltriphenylphosphonium iodide (3.21 g, 7.96 mmol) was added to 30 mLof THF. Then 5 mL of 1.6 M BuLi was added slowly to the solution. After2 h stirring the solution turned bright yellow. The solution was cooledto −78° C. and a solution of 4.6 g (3.98 mmol) of2-isoproproxy-5-(polyisobutyl)benzaldehyde ether in THF was added slowlyto the mixture. The reaction was stirred overnight. The solvent wasremoved under reduced pressure and then 100 mL of hexanes was added tothe viscous residue. The hexanes solution was washed first with 75 mL ofdimethyl formamide three times and then with 75 mL of 90% ethanol/waterthree times. The hexanes phase was dried over sodium sulfate. Thesolvent was removed under reduced pressure to yield the1-isoproproxy-4-(polyisobutyl)-2-vinylbenzene product as a light yellowviscous residue with 80% yield. ¹H NMR (500 MHz, CDCl₃), δ: 0.8-1.8 (m,168H), 1.8 (s, 2H), 4.51 (m, 1H), 5.73 (dd, J=1.71, 11.23 Hz, 1H), 5.73(d, J=1.46, 17.82 Hz, 1H), 6.81 (d, J=8.54 Hz, 1H), 7.07 (dd, J=10.98,17.82 Hz, 1H), 7.19 (dd, J=2.45, 8.55 Hz, 1H), and 7.46 (d, J=2.44 Hz1H). ¹³C NMR (125 MHz, CDCl₃), δ: 153.13, 142.54, 132.96, 127.11,126.71, 124.62, 113.98, 113.67, 71.11, multiple peaks between 58-60,38-38.5, and 30.75-33.

PIB-Supported Grubbs-Hoveyda Second Generation Catalyst

A mixture of 2 g (1.72 mmol) of1-isoproproxy-4-(polyisobutyl)-2-vinylbenzene, 0.12 g (1.21 mmol) ofCuCl, and 0.73 g (0.86 mmol) of the second generation Grubbs catalyst indichloromethane was stirred at 40° C. overnight. The solution turnedfrom red to green as the reaction progressed. The solvent was removedunder reduced pressure and the residue was purified by columnchromatography (2:1 hexane:dichloromethane) to yield a dark greenviscous solution. The solvent was removed under reduced pressureresulting in dark green viscous residue of the PIB-supported catalystproduct (87% yield). ¹H NMR (500 MHz, CDCl₃), δ: 0.8-1.8 (m, 156H), 1.8(s, 2H), 2.42-2.49 (m, 18H), 4.20 (s, 4H), 4.87 (m, 1H), 6.71 (d, J=8.7Hz, 1H), 6.87 (d, J=1.83 Hz, 1H), 7.09 (s, 4H), 7.48 (dd, J=2.06, 9.15Hz, 1H), and 16.32 (s, 1H). ¹³C NMR (125 MHz, CDCl₃), δ: 298.35 (m),212.65, 150.40, 145.13, 145.11, 138.97, 129.58, 129.57, 129.55, 127.55,120.59, 112.25, 74.81, multiple peaks between 58-60, 38-38.5, and30.75-33. λ_(max)=591 nm. IR (KBr, br: broad, s: strong, m: medium, w:weak): 2954 (br), 2870 (br), 1729 (w), 1612 (w), 1592 (w), 1488 (s),1455 (m), 1391 (s), 1367 (s), 1297 (m), 1267 (s), 1232 (s), 1139 (m),1108 (m), 1037 (m), 927 (m), 854 (m), 815 (m), 739 (S), 704 (m), 649(m), 621 (w), 580 (m).

Procedures and Product Characterization Data for Metathesis Reactions.

Conversion of substrate 8 to product 9 (Table 1):

A mixture of 120 mg (0.5 mmol) substrate 8 and 40 mg (0.025 mmol) ofcatalyst 7 were dissolved in 5 mL of heptane. The reaction was stirredfor 1 h. Once the reaction was completed, 3 mL of acetonitrile was addedto the reaction mixture and the biphasic mixture was stirred vigorously.After a gravity separation, the acetonitrile layer was removed. Thesolvent was removed from this phase under reduced pressure to yieldcompound 9 (Yao and Zhang, 2003). ¹H NMR (500 MHz, CDCl3), δ: 1.24 (t,J=7.33 Hz, 6H), 3.0 (s, 4H), 4.19 (q, J=7.32 Hz, 4H), and 5.60 (m, 2H).¹³C NMR (125 MHz, CDCl₃), δ: 172.49, 128.05, 61.76, 59.07, 41.08, and14.27.

Conversion of Substrate 16 to Product 17 (Table 1):

A mixture of 127 mg (0.5 mmol) substrate 16 and 40 mg (0.025 mmol) ofcatalyst 7 were dissolved in 5 mL of heptane. The reaction was stirredfor 1 hour. Once the reaction was completed, 3 mL of acetonitrile wasadded to the reaction mixture and stirred vigorously. After both phasesof the solvent are separated, the acetonitrile layer was removed. Theheptane layer was recycled in the subsequent reactions. The solvent wasremoved under reduced pressure to yield compound 17 (Romero et al.,2004). ¹H NMR (500 MHz, CDCl₃), δ: 1.25 (m, 6H), 2.12 (m, 4H), 2.56 (s,2H), 4.19 (m, 4H), and 5.68 (m, 2H). ¹³C NMR (125 MHz, CDCl₃), δ:171.84, 126.31, 124.24, 61.49, 53.16, 30.64, 27.57, 22.54, and 14.27.

Conversion of Substrate 10 to Product 11 (Table 1):

In a second procedure, a ring-closing metathesis reaction was carriedout where the product self-separated from the heptane solution of thecatalyst. In this reaction, a mixture of 125 mg (0.5 mmol) of substrate10 (Yao and Zhang, 2003) and 40 mg (0.025 mmol) of catalyst 7 weredissolved in 5 mL of heptane. The reaction was stirred for 1 h. As thereaction proceeded, product 11 precipitated out of solution; thereforeit was separated from the reusable heptane solution of the catalyst anddried under reduced pressure. The heptane layer was directly recycled insubsequent reactions. ¹H NMR (500 MHz, CDCl₃), δ: 2.44 (s, 3H), 4.13 (s,4H), 5.66 (s, 2H), 7.33 (d, J=8.1 Hz, 2H), and 7.73 (d, J=8.3 Hz, 2H).¹³C NMR (125 MHz, CDCl₃), δ: 143.68, 134.53, 130.0, 127.67, 125.70,55.08, and 21.78. M.P. range=123.2-126.5° C.

Conversion of Substrate 12 to Product 13 (Table 1):

A second example of a self-separating product involved the dienesubstrate 12. A mixture of 125 mg (0.5 mmol) of the substrate 12 and 40mg (0.025 mmol) of catalyst 7 were dissolved in 5 mL of heptane. Thereaction was stirred for 1 h. As the reaction proceeded, product 13precipitated out of solution. It was separated from the catalystsolution by filtration and dried under reduced pressure. The heptanelayer was directly recycled in subsequent reactions. ¹H NMR (500 MHz,CDCl₃), δ: 1.66 (s, 3H), 2.43 (s, 3H), 3.97 (m, 2H), 4.07 (m, 2H), 5.25(m, 1H), 7.32 (d, J=8.1 Hz, 2H), and 7.72 (d, J=8.2 Hz, 2H). ¹³C NMR(125 MHz, CDCl₃), δ: 143.58, 135.31, 129.97, 127.70, 11932, 117.84,57.92, 55.37, 21.78, and 14.32. M.P. range=100.8-101.8° C.

Conversion of Substrate 14 to Product 15 (Table 1):

A mixture of 125 mg (0.5 mmol) substrate 14 and 40 mg (0.025 mmol) ofcatalyst 7 were dissolved in 5 mL of heptane. The reaction was stirredfor 1 h. As the reaction proceeded, product 15 precipitated out ofsolution. After 1 h, the product was separated from the heptane solutionof the catalysts by filtration. The heptane catalyst solution wasdirectly recycled in subsequent reactions. The product was dried andcharacterized. ¹H NMR (500 MHz, CDCl₃), δ: 2.24 (m, 2H), 2.45 (s, 3H),3.19 (t, J=5.61 Hz, 2H), 3.59 (m, 2H), 5.63 (m, 1H), 5.77 (m, 1H), 7.34(d, J=8.06 Hz, 2H), and 7.70 (d, J=8.3 Hz, 2H). ¹³C NMR (125 MHz,CDCl₃), δ: 143.73, 133.62, 129.86, 127.95, 125.31, 123.0, 45.02, 42.88,25.51, and 21.77. M.P. range=99.7-102.2° C.

Ring-Opening of Substrates 18 and 19 (FIG. 4):

Catalyst 7 (20 mg, 0.012 mmol) was dissolved in 2 mL of THF. It was thenadded dropwise to a THF solution (5 mL) of the substrate monomer (18:60.9 mg, 0.37 mmol, 30 equiv.; 19: 60.5 mg, 0.37 mmol, 30 equiv.) andthe reaction was stirred at room temperature. The color of the solutionturned from green to light gray in less than 2 min. The solution wasstirred for an additional 20 min, then ethyl vinyl ether (0.4 mL, 600equiv.) was added and stirring continued for 15 min. The polymerizationsolution was then poured into methanol (100 mL) while stirring to give alight greenish solid that was collected and dried under vacuum.

Ruthenium Analysis Procedure:

The sample that was to be analyzed (20-30 mg) was added to a 20 mL vialalong with 4 g of concentrated nitric acid. The mixture was heated to120° C. until everything dissolved. At this point 4 g of concentratedsulfuric acid was added to the solution. The solution was then allowedto stand at room temperature for 24 h. At this point, the concentratedacidic aqueous solution was transferred to a 50-mL plastic bottle anddiluted to 50 mL with 1% nitric acid solution. A portion (0.2063 g) ofthe solution was further diluted to 50 mL with an additional portion of1% nitric acid. Then, the diluted sample solution was analyzed byICP-MS.

Study 2

Polyisobutylene (PIB) Phase-Anchored N-heterocyclic carbene Ligands.

Molecules 2-23 as discussed in the below text for this study refer tocertain molecules shown throughout the Materials and methods (Study 2)section and Table 2. These numbers do not refer back to the moleculesdescribed in Study 1.

N-Heterocyclic carbenes (NHC) have become widely used ligands fororganometallic chemistry since Arduengo's initial reports (Arduengo etal., 1991). While their use in metathesis chemistry is most common,metal complexes derived from these structurally diverse ligands areuseful in many catalytic processes (Liddle et al., 2007; Glorius, 2007).N-Heterocyclic carbenes themselves are useful organocatalysts too(Marion et al., 2007). Thus, there is significant interest in strategiesthat facilitate separation, recovery and reuse of these ligands andtheir metal complexes. Below are described new routes to recoverable,heptane-soluble NHC ligands and their use as supports for recoverable,reusable metathesis catalysts.

Insoluble cross-linked polymers or inorganic supports for recoverablereusable NHC-ligated metal complexes useful in catalysis are known(Clavier et al., 2007). Examples of soluble polymer supports for thesecatalysts have also been described, but these latter reports are limitedto the use of poly(ethylene glycol) (PEG) supports (Hong and Grubbs,2006; Zeitler and Mager, 2006). PEG supports attached to an imidazoliumcarbon or to an imidazolium nitrogen yield NHC catalysts that arewater-soluble or recoverable by solvent precipitation. Described in thisexample is the use of heptane-soluble polyisobutylene (PIB) phaseanchors (Li et al., 2005) to prepare separable NHC metal complexes. Asshown below, PIB groups can be attached to these carbene precursors andthe product PIB-bound NHCs form metal complexes that are phaseselectively soluble in the heptane phase of thermomorphic mixtures ofheptane and polar solvents. Alternatively heptane solutions of theseNHCs can be extracted with polar solvents with minimal losses of themetal complex. This behavior is demonstrated both for Ag(I) complexesand with separable, recoverable, and reusable Ru catalysts useful inring closing metatheses.

Three approaches were explored to synthesize PIB-supported NHC ligands.First, a Friedel-Crafts alkylation of a commercially available mixtureof alkene-terminated PIBs afforded 2,6-dimethyl-4-(polyisobutyl)aniline(molecule 2) which, like mesityl amine, reacts with oxalyl chloride toform the diamide (molecule 3). This reaction used excess 2 which wasseparated using an Amberlyst resin as a scavenger (Liu et al., 1998).The diamide product was then reduced to form a diamine that wasconverted into the PIB-bound imidazolium tetraborofluorate salt(molecule 4) using known chemistry (Hong and Grubbs, 2006).

A second route to PIB-bound NHC ligands that has also been used byZeitler's group to synthesize PEG-bound NHCs uses a ‘Click’cycloaddition of a mono- or di-propargylic imidazole derivative with asoluble polymeric azide (Zeitler and Mager, 2007; Wu and Fokin, 2007).

Formation of metal complexes from the imidazolium salts used eitherKHMDS to deprotonate 4 to synthesize a PIB-supported Hoveyda-Grubbssecond generation catalyst (molecule 8) from the Hoveyda-Grubbs firstgeneration catalyst 7 (Hong and Grubbs, 2006) or used Ag₂O (Wang andLin, 1998) to react with 6 or 9 to prepare the Ag(I) complexes(molecules 10 and 11).

These metal complexes were characterized by solution-state ¹H and ¹³CNMR spectroscopy. Both the PIB-bound pincer compound 10 and compound 11had spectra that were like those of low molecular weight pincer Ag(I)complexes formed using octadecylazide in place of the PIB azide. In thecase of 11, the carbene carbon also exhibited C—Ag coupling. An analysisfor Ag showed that 10 or 11 contained 4.06% or 3.51% Ag (4.05% or 3.89%Ag was expected for 10 or 11 if the PIB groups in the product have adegree of polymerization of 20). ICP-MS analyses showed that the Ag(I)complex 10 had 98:2, 99:1, or 96:4 selective solubility in heptane inmixtures of heptane with CH₃CN, AcOCH₂CH₂OAc, or DMF. Complex 11 had a98:2 phase selective solubility in a partially thermomorphicheptane/CH₃CN mixture. The phase selective solubility of 11 in theheptane phase of an equivolume heptane/CH₃CN mixture was completelydifferent than that of the lower molecular weight analog (molecule 12).ICP-MS showed the heptane phase selective solubility for 12 was <1:1000,which represents a >1000-fold difference.

Studies of the phase selective solubility of the Ru complex 8 and itslower molecular weight analog (molecule 13) mirrored those for the Agcomplexes. A UV-vis analysis showed a 1000-fold difference of 99:1 vs1:100 heptane phase selective solubility when 8 or 13 was present in athermomorphic equivolume mixture of heptane and CH₃CN. These UV-visiblespectroscopy results are apparent in a visual inspection (FIG. 9a-c ) ofthe reactions and were confirmed by ICP-MS analyses that showed a 97:3versus a 1:99 phase selective solubility for 8 and 13 in the heptanephase of a heptane/CH₃CN mixture.

Ru catalytic complexes such as 8 are structurally analogous to the Rucomplex 13 already used in ring-closing metathesis (Garber et al.,2000). However, unlike 13, 8 could be recycled in up to twenty reactioncycles to convert a variety of 1,6-dienes and 1,7-dienes into cyclicolefins at room temperature (Table 2). Recycling of catalyst 8 wasaccomplished in one of two ways. The first approach for performingring-closing metathesis of dienes 14 and 22 (Table 2) employed heptaneas a solvent, afterwhich product was extracted with CH₃CN. In thisapproach, the less dense heptane phase containing catalyst 8 was reusedby simply adding fresh substrate. Products 15 and 23 (Table 2) were thenisolated by removal of the CH₃CN.

TABLE 2 Ring-closing metathesis reactions with catalyst 8^(a).

product cycle 1 cycle 2 cycle 3 cycle 4 cycle 5 15 60% 75% 85% 94% 94%17^(b) 72% 81% 99% 99% 98% 19 67% 75% 93% 99% 99% 21 59% 76% 84% 93% 93%23 62% 71% 97% 99% 99% ^(a)Yields in cycles 1-5 are for isolatedproducts in 0.5 mmol scale reactions and increase cycle to cycle becauseof saturation of the catalyst-containing heptane phase by reactionproducts. ^(b)20 cycles (average yield of 97% per cycle) were carriedout with reaction times of two hours in the 12th-13th cycles, four hoursin 14th-18th cycles, and eight hours in 19th-20th cycles.

While most catalyst recovery schemes focus on catalyst separation, thesolubility of catalyst 8 in heptane and the low solubility of manyorganic compounds in heptane allowed the use of another recycling schemefor substrates 16, 18, and 20 (Table 2). In these cases, startingmaterials were soluble in a heptane solution containing catalyst 8;however, the products resulting from catalysis precipitated fromsolution, thereby effectively separating themselves from the catalyst.In these cases, products 17, 19, and 21 (Table 2) were recovered bysimple filtration; recycling of the catalyst only required adding afresh heptane solution of substrate to the recovered solution containing8.

The recyclability/recoverability of catalyst 8 was evaluated by ICP-MSanalysis. Samples of product 17 (Table 2) from the first, second, fifth,and fourteenth reaction cycles were digested in concentrated nitric acidand then in sulfuric acid. The ICP-MS results showed that only0.28-0.54% of the starting Ru was in the product phase. This level ofleaching of Ru from the catalyst phase is comparable to that seen for awater-soluble PEG-supported SIMes (Hong and Grubbs, 2007). Moreover, themetal leaching is approximately 10-fold less than that observed for theRu catalyst that incorporated a PIB-bound benzylidene ligand (describedin Study 1; Hongfa et al., 2007).

Materials and Methods Study 2)

General

The ¹H-NMR spectra were recorded on an Inova 500 MHz and 300 MHzspectrometer operating at 499.95 MHz and 299.916 MHz, respectively.¹³C-NMR spectra were recorded on an Inova 500 MHz spectrometer operatingat 125.719 MHz. Chemical shifts were reported in parts per million (δ)relative to residual proton resonances in the deuterated chloroform(CDCl₃). Coupling constants (J values) were reported in hertz (Hz), andspin multiplicities are indicated by the following symbols: s (singlet),d (doublet), dd (doublet of doublet), t (triplet), q (quartet), b(broad), and m (multiplet). UV-Vis spectra were obtained using Agilent8453 UV-Visible spectrometer. ICP-MS data were obtained using a PerkinElmer DRC II instrument.

All reactions were carried out under an inert atmosphere unlessotherwise noted. Acetonitrile, heptane, dim ethylformamide, ethanol,dichloromethane, tetrahydrofuran, and toluene were purchased from EMDand used as received. Polyisobutylene was obtained from BASF. All otherchemicals were obtained from Sigma-Aldrich and used as received.

Synthesis of PIB-Supported NHC, Grubbs-Hoveyda 2nd Generation Catalyst,and Ag(I) Complexes 2,6-Dimethyl-4-(polyisobutyl)aniline (molecule 2)

A mixture of 12.4 g (102 mmol) of 2,6-dimethylaniline, 10.15 g (10.15mmol) of polyisobutylene (Glissopal® 1000), and 4.4 g (33 mmol) ofaluminum trichloride was stirred for 3 d at 200° C. in a pressurevessel. After 3 d, the deep purple solution reaction was cooled toapproximately 100° C. and added to 200 mL of hexane. The solution soformed was washed with 150 mL of dimethylformamide three times and thenwith 150 mL of 90% ethanol/water three times. After drying over sodiumsulfate, the solvent was removed under reduced pressure and the productwas purified by column chromatography (eluted first with hexane and thenwith dichloromethane). Solvent removal afforded the product as a lightyellow viscous residue. The yield was 65% (7.39 g). ¹H-NMR (500 MHz,CDCl₃), δ: 0.8-1.6 (m, 140H), 1.8 (s, 2H), 2.19 (s, 6H), 3.45 (s, 2H),and 6.92 (s, 2H). ¹³C-NMR (125 MHz, CDCl₃), δ: 18.26, multiple peaksbetween 30-40 and 58-60, 121.28, 126.30, 140.06, and 140.27.

N,N′-Bis(2,6-dimethyl-4-(polyisobutyl)phenyl)oxalamide (molecule 3)

A mixture of 6 g (5.35 mmol) of 2,6-dimethyl-4-(polyisobutyl)aniline and0.64 g (6.3 mmol) of triethylamine in 30 mL of dichloromethane wascooled to 0° C. A solution of oxalyl chloride (0.4 g, 3.15 mmol) in 5 mLof dichloromethane was added slowly to the reaction. The reaction wasthen stirred overnight. The solvent was removed under reduced pressureand added to 150 mL of hexane. The hexane solution was washed with 100mL of 90% ethanol/water three times. The hexane phase was dried oversodium sulfate and shaken with 6 g of acid Amberlyst XN-1010 for 4 h,and then the resin was removed by filtration. The solvent was removedunder reduced pressure to yield a light yellow viscous residue. Theyield was 88% (5.40 g). ¹H-NMR (500 MHz, CDCl₃), δ: 0.8-1.6 (m, 280H),1.82 (s, 2H), 2.28 (s, 12H), 7.11 (s, 2H), and 8.82 (s, 2H). ¹³C-NMR(125 MHz, CDCl₃), δ: 18.26, multiple peaks between 30-40 and 58-60,126.20, 129.30, 134.05, 150.15, and 158.25.

N,N′-Bis(2,6-dimethyl-4-(polyisobutyl)phenyl)ethane-1,2-diamine

6.34 g (2.76 mmol) ofN,N′-bis(2,6-dimethyl-4-(polyisobutyl)phenyl)oxalamide was dissolved in30 mL of toluene, then 1.83 mL (18.67 mmol) of BH₃—SMe₂ was added to thesolution. The solution turned from yellow to almost colorless. Thereaction was heated at 90° C. overnight. The solvent was removed underreduced pressure and purified by column chromatography(10:1/hexane:dichloromethane). Solvent removal afforded a light yellowviscous residue. The yield was 61% (3.82 g). ¹H-NMR (500 MHz, CDCl₃), δ:0.8-1.6 (m, 280H), 1.77 (s, 2H), 2.30 (s, 12H), 3.17 (s, 4H), and 6.97(s, 4H). ¹³C-NMR (125 MHz, CDCl₃), δ: 18.26, multiple peaks between30-40 and 58-60, 49.30, 126.96, 128.92, 143.23, and 144.18.

N,N′-(Ethane-1,2-diylidene)bis(2,6-dimethyl-4-(polyisobutyl)aniline)

A mixture of 3.85 g (3.43 mmol) of 2,6-dimethyl-4-(polyisobutyl)aniline,and a catalytic amount of formic acid in 13 mL of hexane was prepared. Asolution of 0.25 g (1.72 mmol) of glyoxal (40% in water) in 4 mL ofisopropanol was then added to this solution. The reaction mixtureinitially turned cloudy for roughly 5 min and then became a clear yellowsolution. The reaction was allowed to stir overnight. The solution wasdried with sodium sulfate and the solvent was removed under reducedpressure to yield a dark yellow/brownish viscous residue. The yield was94% (3.65 g). ¹H-NMR (500 MHz, CDCl₃), δ: 0.8-1.6 (m, 280H), 1.77 (s,2H), 2.20 (s, 12H), 7.06 (s, 4H), and 8.12 (s, 2H). ¹³C-NMR (125 MHz,CDCl₃), δ: 18.90, multiple peaks between 30-40 and 58-60, 126.06,126.46, 128.50, 147.10, and 163.68.

1,3-Bis(2,6-dimethyl-4-(polyisobutyl)phenyl)imidazolium chloride

0.55 g (0.24 mmol) ofN,N′-(ethane-1,2-diylidene)bis(2,6-dimethyl-4-(polyisobutyl)aniline) wasdissolved in 2 mL of THF and 23 mg (0.24 mmol) of chloromethyl ethylether was added and heated to 40° C. overnight. The solvent was removedtinder reduced pressure and the residue was purified by columnchromatography (dichloromethane). Solvent removal afforded a light brownviscous residue. The yield was 65% (0.36 g). ¹H-NMR (500 MHz, CDCl₃), δ:0.8-1.6 (m, 280H), 1.82 (s, 2H), 2.20 (s, 12H), 7.19 (s, 4H), 7.79 (s,2H), and 10.21 (s, 1H). ¹³C-NMR (125 MHz, CDCl₃), δ: 18.90, multiplepeaks between 30-40 and 58-60, 125.36, 127.44, 130.51, 133.57, 139.20,and 154.63.

1,3-Bis(2,6-dimethyl-4-(polyisobutyl)phenyl)-4,5-dihydro-imidazoliumtetrafluoroborate (molecule 4)

3.62 g (1.6 mmol) ofN,N′-bis(2,6-dimethyl-4-(polyisobutyl)phenyl)ethane-1,2-diamine wasdissolved in 10 mL of triethyl orthoformate and followed by the additionof 230 mg (2.19 mmol) of ammonium tetrafluoroborate and heated to 110°C. overnight. The solvent was removed under reduced pressure andpurified by column chromatography (9:1/dichloromethane:methanol)resulted in a dark yellow viscous residue. The yield was 79% (2.99 g).¹H-NMR (500 MHz, CDCl₃), δ: 0.8-1.6 (m, 280H), 1.85 (s, 2H), 2.42 (s,12H), 4.65 (s, 4H), 7.17 (s, 4H), and 7.65 (s, 1H). ¹³C-NMR (125 MHz,CDCl₃), δ: 18.36, multiple peaks between 30-40 and 58-60, 52.37, 127.60,129.84, 134.54, 154.11, and 158.25.

1,3-Bis-((1-polyisobutyl-1H-1,2,3-triazol-4-yl)methyl)imidazoliumbromide (molecule 6)

0.606 g (2.69 mmol) of 1,3-di-(prop-2-ynyl)imidazolium bromide (molecule5), 17 mg (0.17 mmol) of CuCl, and 6.17 g (5.92 mmol) ofazide-terminated polyisobutylene were dissolved in 105 mL ofdichloromethane and 20 mL of methanol. The solution was stirred at roomtemperature for 24 h. After the reaction was completed, 1.19 g of EDTAand 20 mL of water was added and stirred at room temperature for 24 h.Dichloromethane layer was separated and remove under reduced pressure,and dissolved in 100 mL of hexane and washed with methanol until themethanol layer became colorless. The hexane was removed under reducedpressure. After the purification by column chromatography (eluted firstwith and then with 9:1/dichloromethane:methanol), the product was anorange vicious residue. The yield was 82% (5.12 g). ¹H-NMR (500 MHz,CDCl₃), δ: 0.6-1.7 (m, 280H), 2.13 (m, 2H), 4.031 (dd, J=6, 13.5 Hz,2H), 4.22 (dd, J=7.4, 13.5 Hz, 2H), 5.61 (s, 4H), 7.44 (s, 2H), 8.21 (s,2H), and 10.85 (b, 1H) ¹³C-NMR (125 MHz, CDCl₃), δ: 20.55, multiplepeaks between 28-39 and 57-60, 123.07, 125.59, 136.64, and 139.64.

1,3-Bis-((1-polyisobutyl-1H-1,2,3-triazol-4-yl)methyl)imidazol-2-ylidene-silver(I)bromide (molecule 10)

0.32 g (0.138 mmol) of1,3-bis-((1-polyisobutyl-1H-1,2,3-triazol-4-yl)methyl)imidazoliumbromide and 17.4 mg (0.075 mmol) of Ag₂O were dissolved in 3 mL ofdichloromethane. The solution was stirred at 49° C. for 24 h. Thesolution was filtered to remove excess silver oxide and the solid waswashed with dichloromethane. The solution was dried with sodium sulfateand solvents were removed under reduced pressure to yield an orangeviscous residue. The yield was 93% (0.313 g). ¹H-NMR (300 MHz, CDCl₃),δ: 0.6-1.8 (m, 280H), 2.10 (m, 2H), 4.02 (dd, J=6, 13.5 Hz, 2H), 4.21(dd, J=7.4, 13.5 Hz, 2H), 5.30 (s, 4H), 7.22 (s, 2H), and 7.68 (s, 2H).¹³C-NMR (125 MHz, CDCl₃), δ: 20.68, multiple peaks between 28-39 and57-60, 121.55, 123.90, 142.14, and 181.16.

1,3-Bis-((1-octadecyl-1H-1,2,3-triazol-4-yl)methyl)imidazol-2-ylidene-silver(I)bromide

158.4 mg (0.194 mmol) of1,3-bis-((1-octadecyl-1H-1,2,3-triazol-4-yl)ethyl)imidazolium bromideand 33.8 mg (0.146 mmol) of Ag₂O were dissolved in 10 mL ofdichloromethane. The solution was stirred at 49° C. for 24 h. Thesolution was filtered through celite to remove excess silver oxide andthe solid was washed with dichloromethane. The solution was dried withsodium sulfate and solvents were removed under reduced pressure to yieldan orange viscous residue. The yield was 94% (0.1688 g). ¹H-NMR (300MHz, CDCl₃): 0.85 (t, J=6.6 Hz, 2H), 1.11-1.35 (m, 60H), 1.866 (m, 4H),4.299 (t, J=7.5 Hz, 4H), 5.365 (s, 4H), 7.216 (s, 2H), 7.794 (s, 2H).¹³C-NMR (CDCl₃): 14.10, 22.66, 26.48, multiple peaks between 28-31,31.89, 46.69, 50.55, 121.58, 123.40, 14243, 181.67. FIRMS (ESI): Calc.for [M-Br]⁺ (¹⁰⁷Ag isotope); 841.5713. Found: 841.6153.

1,3-Bis-(2,6-dimethyl-4-(polyisobutyl)phenyl)imidazol-2-ylidene-silver(I)chloride (molecule 11)

0.4268 g (0.185 mmol) of1,3-bis(2,6-dimethyl-4-(polyisobutyl)phenyl)imidazolium chloride(molecule 9) and 30.8 mg (0.133 mmol) of Ag₂O were dissolved in 4 mL ofdichloromethane. The reaction was refluxed for 16 h. After the reactionwas cooled to room temperature, it was filtered through celite to removeexcess Ag₂O. The solution was centrifuged at 5° C. to separate the finersilver salt. Solvent was removed under reduced pressure to yield anorange residue. The yield was quantitative (0.4667 g). ¹H-NMR (300 MHz,CDCl₃), δ: 0.7-1.9 (m, 280H), 2.09 (s, 12H), 7.09 (s, 2H), and 7.15 (s,4H). ¹³C NMR (125 MHz, CDCl₃), δ: 18.36, multiple peaks between 30-40and 57-61, 122.68, 126.71, 133.76, 134.92, 152.39, and 182.875 (dd,J(¹³C-¹⁰⁷Ag)=236.6 Hz, J(¹³C-¹⁰⁷Ag)=271.6 Hz).

PIB-Supported Grubbs-Hoveyda 2nd Generation Catalyst (Molecule 8)

A mixture of 1.14 g (0.48 mmol) of1,3-bis(2,6-dimethyl-4-(polyisobutyl)phenyl)-4,5-dihydro-imidazoliu mtetrafluoroborate, 0.15 g (0.75 mmol) of KHMDS, 0.05 g (0.5 mmol) ofCuCl and 0.36 g (0.57 mmol) of 1^(st) generation Hoveyda-Grubbs catalyst(molecule 7) was prepared was dissolved in 5 mL of toluene. The solutionwas heated to 100° C. for 3 hours. Solvent was removed under reducedpressure and purified by column chromatography (dichloromethane)resulting in a dark green viscous residue. The yield was 60% (0.75 g).¹H-NMR (500 MHz, CDCl₃), δ: 0.8-1.6 (m, 280H), 1.87 (s, 2H), 2.41 (b,6H), 2.62 (b, 6H) 4.15 (s, 4H), 4.90 (m, 1H) 6.8 (m, 2H), 6.98 (m, 1μl), 7.22 (b, 4H), 7.47 (m, 1H), and 16.67 (s, 1H). ¹³C NMR (125 MHz,CDCl₃), δ: 21.62, multiple peaks between 30-40 and 58-60, 113.10,122.42, 123.09, 126.53, 127.01, 129.69, 137.30, 139.21, 145.41, 145.44,152.16, 152.43, 152.45, 211.19, and 297.23 (m).

Procedures for Ring Closing Metathesis Reaction

Conversion of Molecule 14 to Molecule 15 (Table 2):

120 mg (0.5 mmol) of substrate 14 and 65 nm g (0.025 mmol) of catalyst 8were dissolved in 5 m L of heptane. After 1 h, the reaction wascomplete. At this point, 3 mL of acetonitrile was added to the reactionmixture. After vigorous stirring, the mixture was allowed to settle andthe two phases were separated. The acetonitrile layer containing theproduct was dried under reduced pressure to yield compound 15. ¹H-NMR(500 MHz, CDCl₃), δ: 1.24 (t, J=7.33 Hz, 6H), 3.0 (s, 4H), 4.19 (q,J=7.32 Hz, 4H), and 5.60 (m, 2H). ¹³C-NMR (125 MHz, CDCl₃), δ: 172.49,128.05, 61.76, 59.07, 41.08, and 14.27.

Conversion of Molecule 16 to Molecule 17 (Table 2):

125 mg (0.5 mmol) of substrate 16 and 65 nm g (0.025 mmol) of catalyst 8were dissolved in 5 m L of heptane. The reaction was stirred for 1 hduring which time the product 17 precipitated from solution. Thecatalyst solution was separated from the product precipitates byfiltration for reuse in a subsequent reaction cycle. The isolated solidproduct was dried under reduced pressure. ¹H-NMR (500 MHz, CDCl₃), δ:2.44 (s, 3H), 4.13 (s, 4H), 5.66 (s, 2H), 7.33 (d, J=8.1 Hz, 2H), and7.73 (d, J=8.3 Hz, 2H). ¹³C-NMR (125 MHz, CDCl₃), δ: 143.68, 134.53,130.0, 127.67, 125.70, 55.08, and 21.78. M.P. range=123.2-126.5° C.

Conversion of Molecule 18 to Molecule 19 (Table 2):

132 mg (0.5 mmol) of substrate 18 and 65 mg (0.025 mmol) of catalyst 8were dissolved in 5 mL of heptane. The reaction was stirred for 1 hduring which time the product 19 precipitated from solution. Thecatalyst solution was separated from the product precipitates byfiltration for reuse in a subsequent reaction cycle. The isolated solidproduct was dried under reduced pressure. ¹H-NMR (500 MHz, CDCl₃), δ:1.66 (s, 3H), 2.43 (s, 3H), 3.97 (m, 2H), 4.07 (m, 2H), 5.25 (m, 1H),7.32 (d, J=8.1 Hz, 2H), and 7.72 (d, J=8.2 Hz, 2H). ¹³C-NMR (125 MHz,CDCl₃), δ: 143.58, 135.31, 129.97, 127.70, 119.32, 117.84, 57.92, 55.37,21.78, and 14.32. M.P. range=100.8-101.8° C.

Conversion of Molecule 20 to Molecule 21 (Table 2):

132 mg (0.5 mmol) of substrate 20 and 65 nm g (0.025 mmol) of catalyst 8were dissolved in 5 mL of heptane. The reaction was stirred for 1 hduring which time the product 21 precipitated from solution. Thecatalyst solution was separated from the product precipitates byfiltration for reuse in a subsequent reaction cycle. The isolated solidproduct was dried under reduced pressure. ¹H-NMR (500 MHz, CDCl₃), δ:2.24 (m, 2H), 2.45 (s, 3H), 3.19 (t, J=5.61 Hz, 2H), 3.59 (m, 2H), 5.63(m, 1H), 5.77 (m, 1H), 7.34 (d, J=8.06 Hz, 2H), and 7.70 (d, J=8.3 Hz,2H). ¹³C-NMR (125 MHz, CDCl₃), δ: 143.73, 133.62, 129.86, 127.95,125.31, 123.0, 45.02, 42.88, 25.51, and 21.77. M.P. range=99.7-102.2° C.

Conversion of Molecule 22 to Molecule 23 (Table 2):

127 mg (0.5 mmol) of substrate 22 and 65 mg (0.025 mmol) of catalyst 8were dissolved in 5 mL of heptane. After 1 h, the reaction was complete.At this point, 3 mL of acetonitrile was added to the reaction mixture.After vigorous stirring, the mixture was allowed to settle and the twophases were separated. The acetonitrile layer containing the product wasdried under reduced pressure to yield compound 23. ¹H-NMR (500 MHz,CDCl₃), δ: 1.25 (t, J=7.08 Hz, 6H), 2.12 (m, 4H), 2.56 (s, 2H), 4.19 (q,J=14.16 Hz, 4H), and 5.68 (s, 2H). ¹³C-NMR (125 MHz, CDCl₃), δ: 171.84,126.31, 124.24, 61.49, 53.16, 30.64, 27.57, 22.54, and 14.27.

Phase Selectivity Studies Procedure

The sample that was to be analyzed (0.12 rug) was dissolved in 12.0 mLof heptane. Then 2 mL of this solution was added to 2 mL of polarsolvent (acetonitrile, ethylene glycol diacetate, di(ethyleneglycol)monomethyl ether or heptane-saturated DMF). The mixture wassealed and heated to 120° C. to generate a homogeneous solution (in thecase of the heptane-acetonitrile system, only partial miscibilityoccurred). The solution was cooled to room temperature and centrifugedfor 1 h at 5° C. to produce a biphasic solution. Part of each phase wasthen analyzed with a UV-Vis spectroscope. Another portion at each phasewas used as a sample for metal analysis.

ICP-MS Digestion Procedure

The sample that was to be analyzed (3-25000 μg) and 4 g of concentratednitric acid were added to a glass vial. The mixture was heated to 120°C. until most compounds were dissolved. At this point, 4 g ofconcentrated sulfuric acid was added to the solution at room temperatureand heated to 120° C. until all of the compounds were dissolved. Thesolution was then allowed to stand at room temperature. At this point,the concentrated acidic aqueous solution was diluted with 1% nitric acidsolution and the diluted sample solution was analyzed by ICP-MS.

All of the compositions or methods disclosed and claimed herein can bemade and executed without undue experimentation in light of the presentdisclosure. While the compositions and methods of this invention havebeen described in terms of preferred embodiments, it will be apparent tothose of skill in the art that variations may be applied to thecompositions and/or methods and in the steps or in the sequence of stepsof the methods described herein without departing from the concept,spirit and scope of the invention. More specifically, it will beapparent that certain agents which are both chemically andphysiologically related may be substituted for the agents describedherein while the same or similar results would be achieved. All suchsimilar substitutes and modifications apparent to those skilled in theart are deemed to be within the scope of the invention.

All patents and publications identified in this application are herebyincorporated by reference in their entirety.

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What is claimed is:
 1. A reaction composition comprising: a) a nonpolarsolvent, wherein the solvent is not latently biphasic; b) a catalystthat is complexed to a nonpolar support comprising polyisobutylene,wherein the catalyst-support complex is dissolved in the solvent; and c)a substrate molecule dissolved in the solvent, wherein the molecule is asubstrate for the catalyst, and wherein the product of a reaction of themolecule with the catalyst is less soluble in the solvent compared tothe molecule.
 2. The composition of claim 1, wherein the product iscompletely insoluble in the solvent.
 3. The composition of claim 1,wherein the solvent comprises an alkane.
 4. The composition of claim 3,wherein the solvent comprises heptane.
 5. The composition of claim 1,wherein the catalyst comprises a metal selected from the groupconsisting of ruthenium, silver and combinations thereof.
 6. Thecomposition of claim 1, wherein the catalyst comprises a rutheniumcatalyst.